Scotch (or in good old Germany Tesa) generates X-rays. No kidding.
A group of scientists at the University of California, Los Angeles have shown that peeling ordinary Scotch tape emits light, including X-rays. The radiation is strong enough to produce an image of the researcher’s finger.
This light release is an example of triboluminescence, which is energy released by mechanical manipulation of solids. The fact that peeling tape emits light and X-rays is not particularly suprising, but the intensity of the X-rays released suggests that the charge density on the tape is ten times more than previously thought. The researchers are now trying to figure out why.
There is, however, no need to worry about using tape. The tape produced X-rays only in a vacuum. (nature.com)
Longer articles: NewScientist (English) & FAZ.Net (German)
Now I'm wondering what sort of image my mom and I were giving when we peeled 15+ Scotch tapes back in August for window-paper...
And for entertaining purposes: Comments of the geeky kind - I thought Duck Tape gave off Quarcks...